In "Undertale", how many main endings are there?

In Undertale, there are three main endings: the True Pacifist Ending, the Neutral Ending, and the Genocide Ending. The game encourages players to befriend and spare all characters as much as possible to achieve the True Pacifist Ending, which is considered the "true" and most fulfilling ending, revealing the full story and providing the most positive outcome. The Neutral Ending occurs when the player has not fulfilled the requirements for either True Pacifist or Genocide, resulting in a conclusion that reflects the player's actions throughout the game. Lastly, the Genocide Ending is obtained by intentionally killing every monster in the game, resulting in a nihilistic conclusion that examines the consequences of the player's destructive actions. These three main endings offer different perspectives and thematic implications, making it a central part of Undertale's narrative experience.